std::experimental::function<R(Args...)>:: operator=

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C++
Experimental
Library fundamentals
Polymorphic allocator library
function & operator = ( const function & other ) ;
(1) (library fundamentals TS)
function & operator = ( function && other ) ;
(2) (library fundamentals TS)
function & operator = ( std:: nullptr_t ) noexcept ;
(3) (library fundamentals TS)
template < class F >
function & operator = ( F && f ) ;
(4) (library fundamentals TS)
(5)
template < class F >
function & operator = ( std:: reference_wrapper < F > f ) ;
(library fundamentals TS)
template < class F >
function & operator = ( std:: reference_wrapper < F > f ) noexcept ;
(library fundamentals TS v3)

Assigns a new target to std::experimental::function . In the description below, let ALLOCATOR_OF ( f ) be the allocator specified in the construction of f , or the value of std:: experimental :: pmr :: get_default_resource ( ) (until library fundamentals TS v3) the default-constructed std:: pmr :: polymorphic_allocator <> value (library fundamentals TS v3) at the time of construction if no allocator was specified.

1) Assigns a copy of target of other , as if by executing function ( std:: allocator_arg , ALLOCATOR_OF ( * this ) , other ) . swap ( * this ) ; .
2) Moves the target of other to * this , as if by executing function ( std:: allocator_arg , ALLOCATOR_OF ( * this ) , std :: move ( other ) ) . swap ( * this ) ; . other is in a valid state with an unspecified value.
3) Destroys the target of * this . * this is empty after the call. The memory resource returned by get_memory_resource() after the assignment is equivalent to the memory resource before the assignment, but the address may change.
4) Sets the target of * this to the callable f , as if by executing function ( std:: allocator_arg , ALLOCATOR_OF ( * this ) , std:: forward < F > ( f ) ) . swap ( * this ) ; . This operator does not participate in overload resolution unless f is Callable for argument types Args... and return type R .
5) Sets the target of * this to a copy of f , as if by executing function ( std:: allocator_arg , ALLOCATOR_OF ( * this ) , f ) . swap ( * this ) ; .

Parameters

other - another std::experimental::function object to copy or move from
f - a callable to initialize the target with
Type requirements
-
F must meet the requirements of Callable .

Return value

* this

Exceptions

1,2,4) Exception thrown on needed allocation of the storage or initialization of the target of * this , if any.
5) (none)

Notes

The move assignment operator may need to allocate storage if get_memory_resource ( ) ! = other. get_memory_resource ( ) (until library fundamentals TS v3) get_allocator ( ) ! = other. get_allocator ( ) (library fundamentals TS v3)

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